Structure for attaching a switch body to a steering column tube

ABSTRACT

A structure for attaching a switch body to a steering column tube, includes a switch body attached to a steering column tube of a vehicle, an adaptor intervening between the switch body and the steering column tube of the vehicle and having a first engaging portion engaged with a locking portion of the steering column tube as well as a second engaging portion engaged with a locking portion of the switch body. The first engaging portion of the adaptor is engaged with the locking portion of the steering column tube, and at the same time, the second engaging portion of the adaptor is engaged with the locking portion of the switch body by pushing the switch body toward the steering column tube side of the vehicle.

The present application is based on Japanese Patent Application No.2007-261707 filed on Oct. 5, 2007, the entire contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a structure for attaching a switch bodyto a steering column tube, in more particular, to a structure in which aswitch body can be easily attached to a steering column tube.

2. Related Art

A switch body mounting a light switch, a wiper switch or the like isattached at an edge of a column tube which supports a steering shaft ofa vehicle. As this type of attachment structure, for example, there isdisclosed a configuration in which an attachment portion extendingoutwards from a rim of an open hole letting a steering column tubepenetrate is extendingly formed on a lower surface of a switch body anda ring-shaped clamping band is fitted over the attachment portion. Theclamping band is a member in which a spring force acts in adiameter-reducing direction and a diameter-expanded state is kept bylocking both edges thereof to a holding portion on the lower surface ofthe switch body.

According to the above-mentioned structure, when attaching a switch bodyto a steering column tube, the switch body is temporarily fixed to thesteering column tube by firstly letting the steering column tube throughan insertion opening of the switch body. When pulling the holdingportion toward the near side in this state, the diameter-expanded stateof the clamping band by the holding portion is released since atemporarily locked state of the both edges of the clamping band with theholding portion is released. Therefore, since the clamping band reducesa diameter by a spring force thereof, the clamping band strongly pressesan assembly portion of the switch body against the steering column tubefrom the periphery, as a result, the switch body is fixed to thesteering column tube.

Patent document 1 JP-A-5-44609U

However, when pressing the switch body against the steering column tubeby the clamping band during switch body attachment, an operation to pullthe holding member toward the near side is required in order to releasethe temporarily locked state of the clamping band, thus, there was aproblem that the amount of man-hours increases and an efficiency ofswitch body attachment is poor. Furthermore, the switch body may beattached to a position where is hard to see from a worker, therefore,there was a countermeasure requirement also from a viewpoint ofworkability and working efficiency.

THE SUMMARY OF THE INVENTION

Therefore, it is an object of the invention to provide a structure forattaching a switch body by which the switch body can be easily attachedto a steering column tube with a single operation.

According to a feature of the present invention, a structure forattaching a switch body to a steering column tube comprises:

-   -   a switch body attached to a steering column tube of a vehicle;    -   an adaptor intervening between the switch body and the steering        column tube of the vehicle and having a first engaging portion        engaged with a locking portion of the steering column tube as        well as a second engaging portion engaged with a locking portion        of the switch body,        -   wherein the first engaging portion of the adaptor is engaged            with the locking portion of the steering column tube, and at            the same time, the second engaging portion of the adaptor is            engaged with the locking portion of the switch body by            pushing the switch body toward the steering column tube side            of the vehicle.

The switch body may be attached by being temporarily assembled with theadaptor and being pushed into the steering column tube in thistemporarily assembled state.

The first engaging portion of the adaptor may be a metal clip attachedby fixing to a predetermined position of the adaptor.

According to present invention, it is possible to provide a structurefor attaching a switch body by which the switch body can be attachedeasily to a steering column tube with a single operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Next, the present invention will be explained in more detail inconjunction with appended drawings, wherein:

FIG. 1 is a perspective view showing a structure for attaching a switchbody to a steering column tube in a first preferred embodiment accordingto the present invention;

FIG. 2 is a revolved section showing the structure for attaching aswitch body to a steering column tube shown in FIG. 1 when viewed fromA-A direction in FIG. 1;

FIG. 3 is a cross sectional view showing a temporarily assembled stateof a switch body 10, a spring 30 and an adaptor 20;

FIG. 4A and FIG. 4B are cross sectional views showing a state ofattachment to a steering column tube 100, wherein FIG. 4A is a statebefore attaching and FIG. 4B is a state after attaching; and

FIG. 5A is a cross sectional view showing a structure for attaching aswitch body to a steering column tube in a second preferred embodimentaccording to the present invention which corresponds to FIG. 2, FIG. 5Bis a cross sectional view showing a structure for attaching a switchbody to a steering column tube in a third preferred embodiment accordingto the present invention which corresponds to FIG. 2 and FIG. 5C is across sectional view showing a structure for attaching a switch body toa steering column tube in a fourth preferred embodiment according to thepresent invention which corresponds to FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT First Preferred EmbodimentAccording to the Present Invention

FIG. 1 is a perspective view showing a structure for attaching a switchbody to a steering column tube in a first preferred embodiment accordingto the present invention. FIG. 2 is a revolved section showing thestructure for attaching a switch body to a steering column tube shown inFIG. 1 when viewed from A-A direction in FIG. 1. FIG. 3 is a crosssectional view showing a temporarily assembled state of a switch body10, a spring 30 and an adaptor 20. FIG. 4A and FIG. 4B are crosssectional views showing a state of attachment to a steering column tube100, wherein FIG. 4A is a state before attaching and FIG. 4B is a stateafter attaching.

As shown in FIG. 1, a structure for attaching a switch body to asteering column tube in the first preferred embodiment according to thepresent invention comprises a switch body 10 attached to a steeringcolumn tube 100 of a vehicle and an adaptor 20 intervening between theswitch body 10 and the steering column tube 100 of the vehicle, in whichthe switch body 10 is attached by being pushed in a state that theadaptor 20 is intervening between the switch body 10 and the steeringcolumn tube 100 mounted on the vehicle side. After the switch body 10 isattached to the steering column tube 100, a non-illustrated rollconnector for electrically connecting electrical components mounted onthe switch body 10 such as various switches or the like with the vehicleside is mounted while allowing rotation of a non-illustrated steeringwheel, furthermore, the steering wheel provided with a non-illustratedcore bar is attached to a steering shaft 101.

(Switch Body 10)

The switch body 10 is provided with a turn lever 11 for a turn signal ona right surface in a state of being rotatable in an upward-downwarddirection and a forward/reverse direction about a proximal end as afulcrum. When the turn lever 11 is operated to an upper side or a lowerside from a neutral position, a connection state of a non-illustratedturn lever switch in the switch body 10 is shifted and a turn signal isemitted corresponding to a lever operation. Furthermore, a wiperoperation lever 12 is provided on a left surface in a state of beingrotatable in an upward-downward direction about a proximal end as afulcrum. When the wiper operation lever 12 is pushed downwards from aninitial position, the connection state of a non-illustrated wiperoperation switch in the switch body 10 is shifted and a wiper isoperated corresponding to a lever operation.

A cylindrical-shaped attachment portion 13 fitted with the adaptor 20 isprovided in a protruding condition on a side where the switch body 10 isattached to the steering column tube 100. Three snap pressing portions13 a are formed on this attachment portion 13 in a circumferentialdirection, which is a portion to push down a below-described snap claw21 formed on the adaptor 20 and is formed having a step 13 d so as topush down the snap claw 21 easily as shown in FIG. 2, furthermore, thestep 13 d is formed in the circumferential direction with apredetermined width so that the snap claw 21 is fitted. Theabove-mentioned step 13 d is not an essential shape, it is acceptable aslong as it is a locking structure in which the snap claw 21 can bepushed down and a movement relative to the snap claw 21 in thecircumferential direction is not allowed, for example, it may be astructure that a concave portion or a hole is formed on an innercircumference of the attachment portion 13 for engaging with the snapclaw 21 or a portion thereof.

Three locking portions 13 b are formed between respective intervals inthe circumferential direction of the above mentioned attachment portion13. In the locking portion 13 b, as shown in FIG. 2, a slit 13 c isformed along an axial direction of the cylindrical-shaped attachmentportion 13, as a result, it is possible to deflect in a radial directionand a locking claw 13 e as a locking portion locked by fitting into ahole 20 a or a notch 20 b of the adaptor 20 is formed on the innercircumference.

Furthermore, a snap ring groove 13 f for fitting a spring 30 is formedin the cylindrical-shaped attachment portion 13 so as to facilitate apositioning of the spring 30 and temporary assembly with the adaptor 20.

In this embodiment, the switch body 10 is mainly formed of a resin (forexample, an ABS resin or the like) and the cylindrical-shaped attachmentportion 13 is formed by being integrally molded, however, it may beformed by assembling two or more parts. Furthermore, thecylindrical-shaped attachment portion 13 may be configured to beindependent as a separate member, to be attached to the steering columntube 100 via the adaptor 20 and to attach the switch body 10 to theattachment portion 13 as this separate member with a screw or the like,for example.

(Adaptor 20)

The adaptor 20 is in a cylindrical shape with steps and the three snapclaws 21 are formed as the first engaging portion thereon in thecircumferential direction. This snap claw 21 is allowed to deflect in aradial direction, is formed so as to be located in a peripheraldirection of the adaptor 20 in the initial state, as shown in FIG. 2 andhas a wedge-shaped convex portion 21 a fitting into a concave portion100 a formed on the below-described steering column tube 100.

Furthermore, three holes 20 a and three notches 20 b are formed as thesecond engaging portion between respective intervals in thecircumferential direction of the above-mentioned three snap claws 21.The locking claw 13 e is fitted into the hole 20 a in the temporarilyassembled state and is fitted into the notch 20 b in a state of beingattached to the steering column tube 100.

The adaptor 20 is formed of a resin or a metal, however, it may beintegrally formed with the snap claw 21 or the like formed of a separatemember. The configuration in which he snap claw 21 is formed with aseparate member will be shown in below-described third and fourthembodiments.

(Steering Column Tube 100)

In the steering column tube 100, the steering shaft 101 is rotatablysupported at a center in a state of being attached to a vehicle side.Three concave portions 100 a for fitting the snap claw 21 of the adaptor20 are formed on the steering column tube 100. A steering wheel providedwith a non-illustrated core bar is attached to a steering shaft 101 soas to penetrate an inner space of the adaptor 20.

(Temporary Assembly of Switch Body 10, Adaptor 20 and Spring 30)

The switch body 10, the adaptor 20 and the spring 30 are temporarilyassembled before being attached to the steering column tube 100. Asshown in FIG. 3, the switch body 10 is temporarily assembled with theadaptor 20 via the spring 30 between them. The three locking claws 13 eon the switch body 10 side are fitted into the hole 20 a on the adaptor20 side. In this temporarily assembled state, since the spring 30imparts a biasing force in a direction to separate the switch body 10and the adaptor 20, there is no backlash between the switch body 10 andthe adaptor 20 and it is possible to push down the adaptor 20 in adirection of the switch body 10.

Three of the above-mentioned snap pressing portions 13 a, the lockingportions 13 b and the locking claws 13 e formed on the attachmentportion 13, the convex portions 21 a and the notches 20 b formed on theadaptor 20 and the concave portions 100 a formed on the steering columntube 100 are provided respectively, however, it is not limited thereto,it is acceptable as long as the attachment portion 13, the adaptor 20and the steering column tube 100 are fixed each other and a designchange for the above-mentioned number of each parts is possible.

(Attachment to Steering Column Tube 100)

FIG. 4A shows an assay product in a state that the switch body 10, theadaptor 20 and the spring 30 are temporarily assembled, which is apreparatory state for being attached to the steering column tube 100. Anattachment operation is carried out by pushing the assay product of thetemporarily assembled state in a direction of the steering column tube100 from this state.

FIG. 4B shows a state that the assay product in the temporarilyassembled state of the switch body 10, the adaptor 20 and the spring 30is attached by being pushed toward the steering column tube 100 side.When pushing the switch body 10 temporarily assembled with the adaptor20 toward the steering column tube 100 side, the adaptor 20 is insertedtoward the steering column tube 100 side and the snap claw 21 comesclose to the concave portion 100 a. At the same time, the distancebetween the switch body 10 and the adaptor 20 decreases and the snapclaw 21 is pushed down in an inner peripheral direction by the snappressing portion 13 a. When further pushing the switch body 10 towardthe steering column tube 100 side, the convex portion 21 a of theadaptor 20 is fitted into the concave portion 100 a, is further pushedstrongly against the attachment portion 13 in the inner peripheraldirection and is fixed due to a locked state of the adaptor 20 with thesteering column tube 100.

Meanwhile, as for the switch body 10 side, the locking claw 13 e fittedwith the hole 20 a of the adaptor 20 is locked by fitting into the notch20 b after sliding onto the outer periphery of the attachment portion 13from the hole 20 a. In this locked state, the switch body 10 is lockedin an axial direction and a circumferential direction, and then, fixed.

The switch body 10 and the adaptor 20 are integrally attached to thesteering column tube 100, locked in the axial direction and thecircumferential direction and fixed by the above-mentioned attachmentoperation.

The structure for attaching a switch body to a steering column tube inthe first preferred embodiment according to the present invention hasfollowing effects.

(1) An easy attachment with a single operation is possible by pushingthe switch body 10 into the steering column tube 100.

(2) Since it is possible to carry out the attachment operation to thesteering column tube 100 in a state that the switch body 10, the adaptor20 and the spring 30 are temporarily assembled, a structure forattaching a switch body with excellent workability is realized.

(3) Since the switch body 10 is temporarily assembled with the adaptor20 via the spring 30, there is no backlash between the switch body 10and the adaptor 20, the attachment operation to the steering column tube100 is facilitated and the workability is improved.

Second Preferred Embodiment According to the Present

FIG. 5A is a cross sectional view showing a structure for attaching aswitch body to a steering column tube in a second preferred embodimentaccording to the present invention which corresponds to FIG. 2. In thissecond preferred embodiment, the switch body 10 is temporarily assembledwith the adaptor 20 omitting the spring 30. Although certain backlashesare generated between the switch body 10 and the adaptor 20 in thetemporarily assembled state, there is no significant obstacle for theattachment operation to the steering column tube 100 and there is aneffect to reduce the cost.

Third Preferred Embodiment According to the Present

FIG. 5B is a cross sectional view showing a structure for attaching aswitch body to a steering column tube in a third preferred embodimentaccording to the present invention which corresponds to FIG. 2. In thisthird preferred embodiment, the switch body 10 is temporarily assembledwith the adaptor 20 omitting the spring 30. Furthermore, in the adaptor20, a metal clip 22 is formed of a separate member and is attached tothe adaptor 20. The metal clip 22 can be made by an insert molding whenmolding the adaptor 20, and also can be attached to the adaptor 20 bypress fitting or screw cramp after molding the adaptor 20. A lockfunction same as the first preferred embodiment is exerted by attachingthe metal clip 22 to the adaptor 20 instead of the snap claw 21.According to the third preferred embodiment, the cost is reduced as thespring 30 is omitted and the attachment strength, improvement of designfreedom or the like are sought by the metal clip 22.

Fourth Preferred Embodiment According to the Present

FIG. 5C is a cross sectional view showing a structure for attaching aswitch body to a steering column tube in a fourth preferred embodimentaccording to the present invention which corresponds to FIG. 2. In thisfourth preferred embodiment, a metal clip 22 is formed of a separatemember and is attached to the adaptor 20. The metal clip 22 can be madeby an insert molding when molding the adaptor 20, and also can beattached to the adaptor 20 by press fitting or screw cramp after moldingthe adaptor 20. A lock function same as the first preferred embodimentis exerted by attaching the metal clip 22 to the adaptor 20 instead ofthe snap claw 21. According to the fourth preferred embodiment, in theadaptor 20, since the switch body 10 is temporarily assembled with theadaptor 20 via the spring 30 between them, there is no backlash betweenthe switch body 10 and the adaptor 20, the attachment operation to thesteering column tube 100 is facilitated and the workability is improved.Furthermore, the attachment strength, improvement of design freedom orthe like are sought by the metal clip 22.

Although the invention has been described with respect to the specificembodiments for complete and clear disclosure, the appended claims arenot to be therefore limited but are to be construed as embodying allmodifications and alternative constructions that may occur to oneskilled in the art which fairly fall within the basic teaching hereinset forth.

1. A structure for attaching a switch body to a steering column tube,comprising: a switch body attached to a steering column tube of avehicle; an adaptor intervening between the switch body and the steeringcolumn tube of the vehicle and having a first engaging portion engagedwith a locking portion of the steering column tube as well as a secondengaging portion engaged with a locking portion of the switch body,wherein the first engaging portion of the adaptor is engaged with thelocking portion of the steering column tube, and at the same time, thesecond engaging portion of the adaptor is engaged with the lockingportion of the switch body by pushing the switch body toward thesteering column tube side of the vehicle.
 2. The structure for attachinga switch body to a steering column tube according to claim 1, whereinthe switch body is attached by being temporarily assembled with theadaptor and being pushed into the steering column tube in thistemporarily assembled state.
 3. The structure for attaching a switchbody to a steering column tube according to claim 1, wherein the firstengaging portion of the adaptor is a metal clip attached by fixing to apredetermined position of the adaptor.
 4. The structure for attaching aswitch body to a steering column tube according to claim 1, wherein thefirst engaging portion of the adaptor is a snap claw allowed to deflectin a radial direction, formed so as to be located in a peripheraldirection of the adaptor in the initial state and formed in acircumferential direction as a wedge-shaped convex portion fitted into aconcave portion formed on the steering column tube.
 5. The structure forattaching a switch body to a steering column tube according to claim 4,wherein a cylindrical-shaped attachment portion fitted with the adaptoris provided in a protruding condition in the switch body and a snappressing portion for pressing the snap claw of the adaptor is formed inthe circumferential direction of the attachment portion.
 6. Thestructure for attaching a switch body to a steering column tubeaccording to claim 4, wherein the switch body is integrally formed ofthe attachment portion and a locking portion with a locking claw byresin molding.
 7. The structure for attaching a switch body to asteering column tube according to claim 4, wherein the switch body has aslit formed along an axial direction of the attachment portion and thelocking portion locked to the adaptor between respective intervals in acircumferential direction of the attachment portion.
 8. The structurefor attaching a switch body to a steering column tube according to claim4, wherein a snap ring groove for fitting a spring into the attachmentportion is formed on the switch body.
 9. The structure for attaching aswitch body to a steering column tube according to claim 4, wherein thesecond engaging portion of the adaptor comprises a hole to which thelocking claw is fitted in a temporarily assembled state and a notch towhich the locking claw is fitted in a state of being attached to thesteering column tube between respective intervals in a circumferentialdirection of the snap claw.
 10. The structure for attaching a switchbody to a steering column tube according to claim 9, wherein thetemporary assembly of the switch body with the adaptor means atemporarily assembled state in which the locking claw on the switch bodyside is fitted into the hole on the adaptor side via a spring betweenthe switch body and the adaptor.